Crocodile predation on a proboscis monkey in Borneo

Abstract

An adult male proboscis monkey (Nasalis larvatus) on the edge of the Sekonyer Kanan River was seized by a crocodile 6 km downstream from the Orangutan Research and Conservation Project base camp where a crocodile had taken a crab-eating macaque (Macaca fascicularis) two years earlier. This incident helps establish false gavials (Tomistoma schlegeli) as important predators on refuging primate populations in southern Borneo and indicates that predation may have influenced the evolution of some behaviors with an antipredator function in bothNasalis andMacaca fascicularis.